Drill-head



(No Model.)

W. R. WRIGHT.

DRILL HEAD.

Patented Feb. 12, 1889.,

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.N. PETERS. mwmm m, Washington, a c

Uirno STATES PATENT @rricE.

lVILLIAM R. IVRIGHT, OF PORT HURON, MICHIGAN.

DRILL-HEAD.

SPECIFICATION forming part of Letters Patent No. 397,769, dated. February 12, 1889.

Application filed $eptemher 28, 1888. Serial No. 286.699. (No model.)

To aZZ whom it may concern;

Be it known that I, WILLIAM R. \Vaion'r, a citizen of the United States, residing at Port Huron, in the county of St. Clair and State of Michigan, have invented new and useful Improvements in Drill-Heads, of which the folthe tube and cut unevenly on its sides.

lowing is a specification.

The invention relates to improvements in drill -heads for removing incrustations in boiler and other tubes, the objects being to provide a drill-head that will quickly and entirely remove said incrustations and will enable the work to be performed by steam-power instead of by hand, by which means all drillheads now in use are operated.

The invention consists in the novel construction of the drill-head, as hereinafter described, illustrated in the drawings, and pointed out in the appended claims.

Figure l of the drawings represents a perspective view of a drill-head embodying the invention. Fig. 2 represents an end View of the same, looking at the point. Fig. 3 represents a drill-head of the kind having a straight stilf rod attached and a flexible driving-shaft attached to the stiff rod.

Referring to the drawings by letter, A designates the drill-head B, the straight stiff rod, preferably of steel, and C the flexible drivingshaft.

The drillhead A is provided in its butt with a central threaded recess, a, for the at tachment of the threaded end of the steel rod 13. The drill'head is provided with the reaming-flanges D, running spirally from point to butt, similarly to screw-threads, which flanges have the cutting-edges (Z and the shoulders d, which are preferably undercut from said edges. The said flanges increase in width from the point to about the middle part of the drill-head and have their outer sides or faces beveled, as at (2 in rear of said middle part, said beveled faces being of increasing width from the middle part to the butt of the drill-head.

The drill-head in the rear of the middle portion is cylindrical, the flanges of equal Width through said portion, and the bevels d i of the edges of the flanges will hold the drillhead aligned within a tube or flue of corresponding bore, so that it will cut equally on all sides, the bevels fitting against the surface of the bore, whereas a drill-head tapered from point to butt would be liable to turn in The flexible tube 0 may be driven by a steamer other motor by any of the usual well-known means, and the straight steel rod has a length equal to that of the tube operated on and is kept aligned or axial therein by the drill-head, the form of which prevents it turning out of alignment.

The steel rod B must be equal in length to the tube operated on, else the bend of the flexible tube might be within said tube, and by coming in contact therewith interfere with the work.

Having described my invention, I claim 1. In a drill-head for removing incrustations from tubes or flues, made tapering from its point to its middle part and cylindrical in rear of the middle part, said drill-head being formed with reaming-flanges extending spirally from the point to the butt, and the said reaming-flanges being provided with bevels or treads on their outer surfaces extending from the middle part to the butt of the drillhead and of gradually increasing Width toward the butt, substantially as set forth.

2. The herein-described drill-head A, having the central threaded recess, a, in its butt, tapered from its point to its middle part, and of equal diameter in rear of said part, and provided with the reaming-flanges D, increasing in width from the point to the middle part of the drill, and provided with the cutting-edges (Z, the undercut shoulders d, and the bevels d substantially as specified.

In testimony that I claim the foregoing as my own Ihave hereto affixed my signature in presence of two witnesses.

WILLIAM R. WRIGHT.

Witnesses:

A. WRIGHT, WALTER ASHLEY. 

